The fogging of optical substrates such as glass and the like has been a persistent nuisance. This fogging phenomena is not only a nuisance, but is actually dangerous when the fogging occurs on substrates such as automobile windows, medical mirrors, medical operating room equipment, etc., due to lack of vision.
Known anti-fog coatings include oil coatings, polymers of glycol-methacrylates and acrylates and polyacrylamides. The oil only left an undesirable film which is difficult to remove, and the known polymers were unable to provide a consistent long lasting anti-fog coating.
There has thus been a constant need for the development of new and more effective anti-fog coatings which are not only more effective for a short period of time, but which remain more effective over a long period of time and under the most adverse conditions. In order for such coatings to be truly effective it is apparent that the same must be optically clear, undetectable, and must provide no visual distortion. In addition the coating must be easy to apply by conventional methods and in the case of the use thereof for medical applications such as dental mirrors, surgical mirrors, etc., the coating must be non-toxic and biocompatible.